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  1. #1
    shred my gnar
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    Chain Slippage...

    ill apologize for my lameness right off the bat but this is driving me nuts... rd issues always kick my rear!!!

    im assuming this is simply a tension (or lack thereof) issue but it cant hurt to ask.

    last few rides ive been getting a fair bit of slipping in the chain on the cassette... ill set it to shift both up and down cleanly and crisply on the stand and even when i ride it around at my house. on the trail as the ride wears on the slipping gets progressively worse... the chain doesnt actually slip down to the next highest gear but just slips in place on whichever cog it is on... typically happens if im in a "too high" gear on a short uphill and im cranking like hell (with or w/o shifting)... then the slipping gets ugly. in fact, i broke a link a couple rides back...

    so... put on a new chain (it was time anyhow) dialed in the rd (i thought) and about 1/3 thru my last ride it starts again and gets REALLY bad. i barrel adjusted, pulled some extra tension on the cable manually, etc. nothing seems to work for very long???

    is this typically a chain-line problem, cable stretched to hell, what gives??? i give up...

    THANKS

  2. #2
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    Yes, it could be a chainline problem.

    Check that the rear hub is not moving from side to side due to loose cone nuts.

    Also check that the crankset is not doing the same thing (can happen often with outboard systems).

  3. #3
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    Check the rd hanger. if it's bent you will get that slipping or "phontom shifting"

  4. #4
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    worn cassette and/or chainring.
    A new chain will likely perform even worse than your old one if you cassette is worn as the old chain was 'mated' with the worn cassette, so to speak.

  5. #5
    shred my gnar
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    right on... forgot to mention the rd hanger had a little crack so it could have been flexing side to side (the rd that is) more than normal, therefore, throwing off the chainline a bit. spaced that in the op... im also replacing the last piece of housing and the cable since it (the housing) has been banged up a bit in that last stretch from the chainstay to the rd.

    i do have an external bb (fsa megaexo) so i will check that and the cone nuts as well... pretty sure there isnt any play in the cranks/bb but i havent checked the rear hub.

    thanks for the responses.

  6. #6
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    arrggg! the new hanger didnt change anything... no play in the cranks/bb or rear wheel. again perfect on the stand and pedaling lightly but as soon as there is a heavy-ish load it is slippage time.

    the cassette and chainrings arent noticeably worn... although i should check that again. both only a bit over a year old with roughly one long-ish ride a week in summer and about half that in the winter.

    also, im not certain but the rd cage looks the slightest bit tweaked possibly... barely enough to make it noticeable. not sure though...

  7. #7
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    Quote Originally Posted by happy_ending
    arrggg! the new hanger didnt change anything... no play in the cranks/bb or rear wheel. again perfect on the stand and pedaling lightly but as soon as there is a heavy-ish load it is slippage time.

    ..
    Your symptoms reek of worn cassette. The kicker is the longer you ride that new chain with a worn drivetrain the more it won't work when you finally do replace that cassette Good luck. Been there, done that.

  8. #8
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    If the rd cage is torqued it will skip definitely. Now you take the gamble. buy a new cassette or a new rd.

  9. #9
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    Quote Originally Posted by eatdrinkride
    Your symptoms reek of worn cassette. The kicker is the longer you ride that new chain with a worn drivetrain the more it won't work when you finally do replace that cassette Good luck. Been there, done that.
    hmmmm... i believe i have dealt with this same issue years ago on another bike (cobwebs clearing) now that you put it that way.

    im picking up what youre putting down but the only thing that doesnt jive is that it was slipping/skipping just as badly with the old chain (which should have matched, right?)... which i blew up. was that just b/c it was worn and the new chain simply makes it worse (by not matching)?

  10. #10
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    Quote Originally Posted by happy_ending

    was that just b/c it was worn and the new chain simply makes it worse (by not matching)?
    Yes. Your cassette and chain will not last forever, even if you keep them 'mated'. Eventually your chain will slip and if the cassette is worn too much (shark toothed looking) a new chain seems to only exasperate the slipping problem. If your cassette was still in good shape a new chain would improve performance for sure.

    Now if you truly have a rd problem then this advice is moot. I'd do this: Put the bike on a stand and shift the bike to middle/middle. Stand behind the bike and look down over/behind the RD/wheel area. Make sure the RD jockey pulleys all line up straight with one another. In other words make sure the lower pulley is not pulled way inward or outward compared to the top pulley. Also be sure the whole chain is in line with itself (chainline) from middle ring to middle cassette cog. If all this looks good and you can smoothly shift through all the rear gears, top to bottom then my money goes on a worn drivetrain. The problem you are having is very common.

  11. #11
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    Does it slip in all the gears? Worn cassettes usually ware in the 3rd and 4th gears first because you ride there most often. If it slips in most of the gears, I'd go with the bent rd. I've had this problem a couple of times and it was the rd every time. I've had cassettes that last for years.

  12. #12
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    Quote Originally Posted by mlepito
    I've had this problem a couple of times and it was the rd every time. I've had cassettes that last for years.

    I've never owned an all steel cassette. I guess one of those would last for years.

    OP: what kind of cassette do you have?

  13. #13
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    Quote Originally Posted by eatdrinkride
    Yes. Your cassette and chain will not last forever, even if you keep them 'mated'. Eventually your chain will slip and if the cassette is worn too much (shark toothed looking) a new chain seems to only exasperate the slipping problem. If your cassette was still in good shape a new chain would improve performance for sure.

    Now if you truly have a rd problem then this advice is moot. I'd do this: Put the bike on a stand and shift the bike to middle/middle. Stand behind the bike and look down over/behind the RD/wheel area. Make sure the RD jockey pulleys all line up straight with one another. In other words make sure the lower pulley is not pulled way inward or outward compared to the top pulley. Also be sure the whole chain is in line with itself (chainline) from middle ring to middle cassette cog. If all this looks good and you can smoothly shift through all the rear gears, top to bottom then my money goes on a worn drivetrain. The problem you are having is very common.
    if only i would have committed to memory what i learned & did the first (2nd or 3rd??) time it happened... i like the progression of stuff to check in order to get to the bottom of it, though.

    as far as what mlepito mentioned... it does seem to be noticably worse in the middle gears... but does seem to slip, at least a little bit, in every gear besides my lowest (biggest). gotta check more closely on that, though. most of the rides i do (flagstaff,az) i am in middle/granny or granny/granny for half the ride (up, up, up) and somewhere in the middle coming back down...

    btw... you guys rock, thanks for the input.

  14. #14
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    Maybe your b-tension screw is not adjusted right:
    http://www.sheldonbrown.com/derailer....html#btension

    A couple rides ago my chain was skipping bad, and it was just because my chain needed to be lubed again; I was surprised as it really wasn't that dry.

  15. #15
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    He probably has a too tight chain link. It makes a bump when it passes through the smaller sized cogs, that might seem to him as if it were skipping. Every time he places the chain, he does it incorrectly, therefore leaving a too tight chain linkage.

  16. #16
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    shimano XT

  17. #17
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    If you have a dual suspension bike and its ghost shifting but you have adjusted the alignment on a bike stand and it works fine but acting up when you ride, then it could be the cable routing from the shifter to the RD.

    As the rear suspension/swingarm move up and down it compress or pull the shifting cable causing it to ghost shift. Intead of a straight run from right shifter to right side top/down tube to RD, try routing it from right shifter to left side of top/down tube and S curve to righ side of swingarm and to RD. I have two bike that was ghost shifting and I can't get rit of it no matter how much adjustment I made or parts change but once I re-route the cable all is well.

  18. #18
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    Quote Originally Posted by Garlock
    He probably has a too tight chain link. It makes a bump when it passes through the smaller sized cogs, that might seem to him as if it were skipping. Every time he places the chain, he does it incorrectly, therefore leaving a too tight chain linkage.
    nope. smooth as butta... no tight links.

  19. #19
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    Quote Originally Posted by fjyang
    If you have a dual suspension bike and its ghost shifting but you have adjusted the alignment on a bike stand and it works fine but acting up when you ride, then it could be the cable routing from the shifter to the RD.

    As the rear suspension/swingarm move up and down it compress or pull the shifting cable causing it to ghost shift. Intead of a straight run from right shifter to right side top/down tube to RD, try routing it from right shifter to left side of top/down tube and S curve to righ side of swingarm and to RD. I have two bike that was ghost shifting and I can't get rit of it no matter how much adjustment I made or parts change but once I re-route the cable all is well.
    i was checking this very thing last night. i have it routed as you suggested but i may have cut the housing a bit short on the "s" curve section going from the left side of the top tube, through the linkage to the right side of the seat stay to the rd. therefore, it may ghost shift (seems like a slip though) while cycling the linkage without enough housing slack in that section.

    anyhow, i have given up and taken it to the lbs... we shall see...

  20. #20
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    Quote Originally Posted by mlepito
    shimano XT
    that is really what ive been thinking all along. if i didnt have to pick-up new shifters to go with a new xt shadow rd i would probably already have the new rd on the bike. i rode an xt on the same bike for 8 friggin years and never replaced it. im on my second sram (destroyed an xo, now on x9) in a year.

    not impressed with sram drivetrain so far.

  21. #21
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    Quote Originally Posted by eatdrinkride
    worn cassette and/or chainring.
    A new chain will likely perform even worse than your old one if you cassette is worn as the old chain was 'mated' with the worn cassette, so to speak.
    bingo. the problem was 110% a worn cassette. it doesnt look bad to me (shark toothed) but the mech at my lbs went through all the same crap i did and settled on the cassette. luckily, my new chain only had a couple rides on it so it seems to work great with the cassette.

    sram gone: xt installed. flawless shifting on a 20 mile ride on sunday...

    another ding on sram, imo. on my old bike i went through 2 xt cassettes in 8 years, new bike i went thru the sram in one year (cant remember the model # but it is equivalent to x9, i believe).

    lame.

  22. #22
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    bingo. the problem was 110% a worn cassette. it doesnt look bad to me (shark toothed) but the mech at my lbs went through all the same crap i did and settled on the cassette. luckily, my new chain only had a couple rides on it so it seems to work great with the cassette.

    sram gone: xt installed. flawless shifting on a 20 mile ride on sunday...


    Cool! I've been down this very same road you have just traveled so glad to hear it's all worked out.

    And I will try an XT cassette next time as well. I have gone through 3 PG980 cassettes in the past 2 to 2 1/2 years.

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